What is ClaudeBot? Anthropic's AI crawler
ClaudeBot is the crawler Anthropic uses to collect web content that could contribute to training its generative AI models.
85 of the 389 major websites we measure block ClaudeBot in robots.txt (22%), making it number 3 of the 30 AI crawlers we track for how often it is blocked. 100 of those sites name it directly in their robots.txt; the rest are covered by a wildcard rule.
Key facts
| Fact | Detail |
|---|---|
| Operator | Anthropic |
| Used for | Anthropic's models |
| Type | Model training. Collects content that may be used to train AI models. Blocking it does not usually remove a site from AI search. |
| robots.txt token | ClaudeBot |
| Operator's documentation | Read it here |
What blocking ClaudeBot does
Anthropic says restricting ClaudeBot signals that a site's future materials should be excluded from its training datasets.
How to allow or block ClaudeBot
Add one of these groups to the robots.txt file at the root of your domain. It is a stated preference that well-behaved crawlers read, not an enforcement mechanism.
User-agent: ClaudeBot Disallow: /
User-agent: ClaudeBot Allow: /
ClaudeBot user agent string
Anthropic's page doesn't list a full string, so look for ClaudeBot in the user agent field of your logs.
How to verify a request is really ClaudeBot
Anyone can put a crawler's name in a user agent string, so the name alone proves nothing. Anthropic says blocking its IP addresses may not work correctly or persistently guarantee an opt-out, because that stops it reading your robots.txt. It says to use robots.txt instead.
How to whitelist ClaudeBot in a firewall or CDN
robots.txt only states a preference. A firewall, CDN or bot protection service can still refuse the request, and the crawler then gets an error even though robots.txt allows it.
- Check that no group in your robots.txt blocks it, using the rule above.
- Add an allow rule in your firewall or CDN that matches the name in the user agent. Keep the rule narrow, because anyone can copy a name.
- Check your server logs for a 200 response from ClaudeBot afterwards.
On Cloudflare, also check AI Crawler and Agent access policies, which can block search, agent and training traffic across a site.
Why ClaudeBot gets a 403 or 405 error
A 403 means the server refused the request, which usually points to a firewall or bot rule. A 405 means the server refused the request's method, so check any rule that only permits certain methods. A crawler that obeys robots.txt won't request a page it is told to avoid, so an error in your logs points to your server's configuration. To stop it deliberately at the server, this nginx rule returns a 403:
if ($http_user_agent ~* "ClaudeBot") {
return 403;
}Which sites recently changed their rules for ClaudeBot?
| Date first seen | Site | Change |
|---|---|---|
| 2 November 2026 | fool.com | Started blocking |
| 19 October 2026 | aliexpress.com | Started blocking |
| 28 September 2026 | airbnb.com | Started blocking |
| 31 August 2026 | fastcompany.com | Started blocking |
| 31 August 2026 | inc.com | Started blocking |
See the full change log.
Who blocks ClaudeBot, by sector
| Sector | Sites measured | Blocking | Share |
|---|---|---|---|
| News publishers | 44 | 35 | 80% |
| Technology media | 25 | 14 | 56% |
| Health publishers | 16 | 6 | 38% |
| Finance and business media | 29 | 9 | 31% |
| Social and media platforms | 28 | 8 | 29% |
| E-commerce and retail | 19 | 4 | 21% |
| Travel | 19 | 4 | 21% |
| Reference and research | 25 | 3 | 12% |
| SaaS platforms | 54 | 2 | 4% |
| AI companies | 28 | 0 | 0% |
| Developer references | 34 | 0 | 0% |
| Government and institutions | 19 | 0 | 0% |
| Hosting and infrastructure | 23 | 0 | 0% |
| SEO and marketing tools | 26 | 0 | 0% |
Sites blocking ClaudeBot
academia.edu, airbnb.com, aliexpress.com, aljazeera.com, amazon.com, apnews.com, arstechnica.com, asahi.com, barrons.com, bbc.co.uk, behance.net, bleepingcomputer.com, bloomberg.com, businessinsider.com, buzzfeednews.com, canva.com, cnbc.com, cnn.com, cntraveler.com, corriere.it, drugs.com, dw.com, ebay.com, economist.com, elpais.com, fastcompany.com, figma.com, flickr.com, fool.com, forbes.com, france24.com, ft.com, globeandmail.com, hackernoon.com, healthline.com, howtogeek.com, huffpost.com, imdb.com, inc.com, instacart.com, investopedia.com, latimes.com, lemonde.fr, lifehacker.com, makeuseof.com, marketwatch.com, mashable.com, medicalnewstoday.com, medium.com, nature.com, nbcnews.com, newsweek.com, newyorker.com, nytimes.com, pcmag.com, pexels.com, pinterest.com, quora.com, reddit.com, reuters.com, and 25 more in the full dataset.
Sites that allow ClaudeBot by name
amplitude.com, bestbuy.com, css-tricks.com, deel.com, delta.com, descript.com, disneyplus.com, frase.io, github.com, hulu.com, jasper.ai, jstor.org, klaviyo.com, monday.com, netflix.com, netlify.com, omio.com, render.com, seranking.com, soundcloud.com, squarespace.com, stability.ai, ulta.com, unsplash.com, venturebeat.com, vimeo.com.
Other Anthropic crawlers
Claude-SearchBot (search indexing), Claude-User (on-demand fetch).
See all 30 AI crawlers, the rule change log or the full study. Being reachable is only the first step: how AI search engines choose what to cite covers the rest.
Cite this data
You are welcome to quote or republish these figures. Please credit IndexHalo with a link to this page (CC BY 4.0). All our datasets are on the data page.
IndexHalo. "ClaudeBot block rate across major websites." Measured 3 November 2026. https://www.indexhalo.com/ai-crawlers/claudebot/
<a href="https://www.indexhalo.com/ai-crawlers/claudebot/">ClaudeBot block rate across major websites, IndexHalo</a>